Struct WithHeader

#[repr(transparent)]
struct WithHeader<H>(NonNull<u8>, PhantomData<H>);

A pointer to type-erased data, guaranteed to either be:

1. NonNull::dangling(), in the case where both the pointee (T) and metadata (H) are ZSTs.
2. A pointer to a valid T that has a header H directly before the pointed-to location.

Tuple Fields

0: NonNull<u8>

1: PhantomData<H>

Implementations

impl<H> WithHeader<H>

fn new<T>(header: H, value: T) -> WithHeader<H>

fn try_new<T>(header: H, value: T) -> Result<WithHeader<H>, AllocError>

Non-panicking version of new. Any error is returned as Err(core::alloc::AllocError).

fn new_unsize_zst<Dyn, T>(value: T) -> WithHeader<H>

where Dyn: Pointee<Metadata = H> + ?Sized, T: Unsize<Dyn>,

unsafe fn drop<T: ?Sized>(&self, value: *mut T)

fn header(&self) -> *mut H

fn value(&self) -> *mut u8

const fn header_size() -> usize

fn alloc_layout(value_layout: Layout) -> Result<(Layout, usize), LayoutError>